A question answer system answers questions posed in a natural language format by applying advanced natural language processing, information retrieval, knowledge representation, automated reasoning, and machine learning technologies. Question answer systems differ from typical document search technologies because document search technologies generate a list of documents ranked in order of relevance based on a word query, whereas question answer systems analyze contextual details of a question expressed in a natural language and provide a precise answer to the question.
Many natural language questions include conditions for which current question answer systems find difficult to interpret. As such, current question answer systems may provide incorrect answers due to text similarity between a question and a document passage.